The New South Wales chief veterinarian and the Department of Primary Industries say they believe an abattoir at the centre of animal cruelty allegations is a rogue operator and not representative of the industry as a whole.

The Hawkesbury Valley Abattoir in north Sydney has been closed after footage aired exclusively on ABC's Lateline showing sheep and cattle which were not stunned properly before slaughter and pigs being beaten repeatedly with an iron bar.

The NSW Food Authority says it closed down the abattoir after viewing video footage which it says reveals "acts of gross animal mistreatment".

Authority spokesman Peter Day has confirmed the abattoir was inspected four times last year without incident.

"There was nothing to indicate the levels of the problems that were revealed in the footage," he said.

"It's absolutely hideous. Last year we saw footage from the live exports of the cattle live exports in Indonesia and some of the most horrific scenes that we saw in that footage was of cattle being slaughtered while fully consciousness, and here in Australia at this abattoir we are seeing the same thing happen," she said.

Ms Hurst is calling for CCTV cameras to be installed inside abattoirs to help prevent animal abuse.

She says a regulator should assess footage periodically to ensure abuses do not happen.

Vet Dr Mark Simpson has compiled a report on the footage, which has also been handed to NSW Police.

He says he believes the footage shows more than 100 breaches of the Prevention of Cruelty to Animals Act.

He says the vision also shows that sheep are not being stunned properly.

"From the time they have their throats slit there shouldn't be any raising of the head, there shouldn't be any voluntary movement," he said.

Dr Simpson says the footage shows one of the animals trying to move its head around while it is bleeding out.

"So it will be losing consciousness but it can still sense what is going on around it," he said.

Earlier, one of the directors of the Hawkesbury Valley Abattoir, Glenn Langley, said he wanted 48 hours so he could take the footage to the regulatory authority and let them examine it.

The abattoir owners say they will not make any comment until the investigation is complete.